Delivery system for vascular implant

ABSTRACT

A medical treatment system and method of treatment is described having an implant that can be positioned and deployed, then undeployed to allow repositioning of the implant. The system includes a self-expanding medical implant that longitudinally foreshortens upon radially expanding from a radially compacted state, a distal interface configured to attach the implant to a distal mount of a delivery device, and a proximal interface configured to attach the implant to a proximal mount of the delivery device. Moving the distal mount longitudinally away from the proximal mount applies a longitudinal tension to the implant causing the implant to expand longitudinally and contract radially, and moving the distal mount toward the proximal mount reduces a longitudinal tension in the implant allowing the implant to expand radially toward a fully expanded state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/572,180, filed Oct. 1, 2009, now U.S. Pat. No. 8,337,541, whichclaims the benefit of U.S. Prov. Appl. No. 61/136,760, filed Oct. 1,2008. The entireties of the above applications are incorporated byreference herein and are to be considered a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical implant insertion deliverysystems and, more particularly, to a delivery device for vascularprostheses.

2. Description of the Related Art

Medical implants, in particular stent-based implants, can be deployed inthe vasculature of patients to treat a variety of ailments and medicalconditions. The fragility of the vascular system tissue and theparticular locations where a vascular prosthesis is requirednecessitates care and precision in the deployment of such implants. Inparticular, heart related implants, often comprising a valve bodysupported by a stent frame, present challenges in locating, positioning,and more specifically repositioning of the stent after partial or fulldeployment of the stent-based implant at a desired location.

A variety of methods and delivery devices aimed at deliveringreplacement heart valves through percutaneous and minimally invasiveapproaches currently exist. A primary challenge of known devices, suchas those disclosed in U.S. Pat. No. 5,411,552 and U.S. Pat. No.6,830,584, is the inability to reposition the replacement valve after itis fully deployed. For example, once a stent, or heart valve frame inparticular, has been expanded via a balloon catheter, there is no way toreduce the diameter of the heart valve frame again. In another example,to deploy an implant comprising a self-expanding nitinol stent and heartvalve body, a delivery device utilizes an outer sheath that is retractedto allow the implant to expand freely to a pre-determined diameter.However, again, once the frame is fully expanded, it cannot be collapsedto adjust, reposition, or remove the implant.

An additional short-coming with the noted delivery systems is that theyare designed solely for use with their respective specific valveimplant. A further short-coming of such approaches is their reliance onradial force as the primary means of fixation and the inability toaccurately position the implant during initial deployment. Theaforementioned devices consist of cylindrical frames, lacking featuresthat can locate the implant relative to a native annulus of a heartvalve. As a result, these devices must rely on external imaging duringthe delivery process, which can lead to improper placement of theimplant and resulting complications and risks to the patient.

SUMMARY OF THE INVENTION

Accordingly, there is a need in the art for an improved medical implantdelivery device that solves some of the disadvantages discussed above.Particularly, there is a need for a delivery device that accuratelypositions an associated implant in a desired position such as, forexample, a native valve annulus, controls the rate at which a frameexpands, and allows the implant to be repositioned and adjusted after ithas reached its full final diameter upon deployment, and before finalrelease of the implant. Further, a need exists for an improved medicalimplant delivery device that does not require radial or longitudinalforce applied and/or transferred to the abutting contact region of thevascular tissue within the patient.

In accordance with one embodiment, the present invention provides amedical treatment system having an implant that can be positioned anddeployed, then undeployed to allow repositioning of the implant whilenot requiring radial or longitudinal force to be applied to the desiredcontract region of the vascular system.

In accordance with another embodiment, the present invention provides amedical treatment system comprising a first elongate support memberhaving a distal mount, a second elongate support member having aproximal mount, the second elongate support member being selectivelymovable relative to the first elongate support member along alongitudinal axis, a self-expanding medical implant that foreshortensupon radially expanding from a radially compacted state, a distalinterface configured to attach the distal mount to the implant, and aproximal interface configured to attach the proximal mount to theimplant. Moving the distal mount away from the proximal mount applies alongitudinal tension to the implant, causing the implant to expandlongitudinally and contract radially and wherein moving the distal mounttoward the proximal mount reduces a longitudinal tension in the implantallowing the implant to expand radially toward a fully expanded state.

In another embodiment, the distal mount is attached to the distalinterface by at least one distal flexible member and the proximal mountis attached to the proximal interface by at least one proximal flexiblemember. In one such embodiment, the distal flexible member and theproximal flexible member comprise a suture.

In another embodiment, the distal interface comprises at least onedistal eyelet and the proximal interface comprises at least one proximaleyelet.

In yet another embodiment, the medical treatment system additionallycomprises a release mechanism configured to release the distal andproximal mounts from the implant.

In yet another embodiment, the distal interface has a length and theimplant has a length in the expanded state, and the distal interfacelength is at least the same as the implant length.

In a further embodiment, the medical treatment system additionallycomprises an endoscope that extends through the first elongate supportmember so as to provide a view adjacent the distal end of the firstelongate support member.

In yet another embodiment, a controller controls the movement of thefirst elongate support member longitudinally relative the secondelongate support member.

In another embodiment, an actuator selectively moves the first elongatesupport member in a longitudinal direction relative to the secondelongate support member.

In a further embodiment, the medical treatment system is in combinationwith a secondary restraint system. In one such embodiment, the secondaryrestraint system comprises a sheath configured to hold the implant atleast partially therein in a compacted state.

In accordance with another embodiment, the present invention provides amedical treatment system that comprises a first elongate support memberhaving a first engagement member and a second elongate support memberhaving a second engagement member, the second elongate support memberbeing selectively movable relative to the first elongate support memberalong a longitudinal axis. The embodiment further includes a distalmount, a proximal mount slidingly coupled relative to the distal mountalong the longitudinal axis, and a first spring interposed between theproximal and distal mounts so as to bias the proximal and distal mountslongitudinally away from one another. The embodiment additionallyincludes a self-expanding medical implant that foreshortens uponradially expanding from a radially compacted state, a distal interfaceconfigured to attach the distal mount to the implant, and a proximalinterface configured to attach the proximal mount to the implant. Movingthe distal mount away from the proximal mount applies a longitudinaltension to the implant causing the implant to expand longitudinally andcontract radially and wherein moving the distal mount toward theproximal mount reduces a longitudinal tension in the implant allowingthe implant to expand radially toward a fully expanded state.

In another embodiment, the proximal and distal mounts are arrangedbetween the first and second engagement members.

In yet another embodiment, at least one of the proximal and distalinterfaces comprises a ring assembly having at least one flexible armfixedly attached to the ring at a first end and releasably attached tothe implant at a second end, the second end extending beyond thediameter of the ring, and wherein the at least one flexible arm isresilient.

In a further embodiment, the first and second engagement members areconfigured so that as the first and second engagement are moved towardone another, the proximal and distal mounts are urged toward each otherand the biasing of the center spring is overcome so that the implantcontracts longitudinally and expands radially.

In one such embodiment, a second spring is interposed between the secondengagement member and one of the proximal and distal mounts, and a thirdspring is interposed between the first engagement member and the otherof the proximal and distal mounts, and the second and third springs eachhave a spring constant greater than a spring constant of the firstspring.

In another such embodiment, the spring constants of the second and thirdsprings are substantially the same.

In accordance with another embodiment, the present invention provides amethod of delivering a medical implant. The method includes providing animplant delivery system comprising a self expanding implant configuredto longitudinally foreshorten upon radially expanding from a compactedradial state, a delivery device comprising proximal and distal mountsthat selectively connect to the implant by a proximal and a distalinterface, respectively, the delivery device configured so that theproximal and distal mounts can be selectively moved relative to oneanother so as to selectively apply a longitudinal tension on the implantto urge the implant into the compacted radial state. The embodimentfurther includes advancing the implant in a compacted radial statewithin a patient to a desired deployment location, positioning theimplant adjacent the desired deployment location, actuating the deliverydevice so as to move the proximal and distal mounts toward one anotherso as to reduce the longitudinal tension on the implant and allow theimplant to radially expand toward a fully expanded state, and verifyingthe implant is properly positioned at the desired deployment locationwithin the patient.

Another embodiment, wherein if it is determined that the implant is notproperly positioned, additionally comprises moving the proximal anddistal mounts away from one another so as to increase the longitudinaltension on the implant to longitudinally expand and radially contractthe implant so as to disengage the implant from the patient's tissues. Afurther such embodiment additionally comprises adjusting the position ofthe implant, and again moving the proximal and distal mounts toward oneanother so as to allow the implant to radially expand.

Yet another embodiment additionally comprises verifying whether theimplant is poised to be properly positioned after partially expandingthe implant.

A further embodiment additionally comprises providing an endoscope, andusing the endoscope to verify whether the implant is properlypositioned.

Other inventive embodiments and features are disclosed below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a medical treatment system in accordancewith an embodiment of the present invention.

FIG. 2A is a side view of a stent frame shown in a compacted state.

FIG. 2B shows the stent frame of FIG. 2A in an expanded state.

FIG. 3A is a side view of a distal assembly of the medical treatmentsystem of FIG. 1.

FIG. 3B is a cross-section view of the distal assembly of the medicaltreatment system of FIG. 3A.

FIG. 4A is a side view of a portion of a delivery device of the medicaltreatment system of FIG. 1.

FIGS. 4B-4H show additional views of detail elements of the deliverydevice shown in FIG. 4A.

FIG. 5 is a perspective view of a portion of the medical treatmentsystem of FIG. 1.

FIG. 6 is an expanded view of a portion of the medical treatment systemof FIG. 1.

FIGS. 7A-C are side views of the insertion and deployment of an implantof the medical treatment system of FIG. 1 at certain stages ofoperation.

FIGS. 8A-D are side views showing certain stages of operation of theextraction of the delivery device of the medical treatment system ofFIG. 1.

FIG. 9 is a perspective view of another embodiment of a distal assemblyof a medical treatment system.

FIG. 10 is a perspective view of an elongate support member of themedical treatment system of FIG. 9.

FIG. 11 is a perspective view of a mount ring of the medical treatmentsystem of FIG. 9.

FIG. 12 is a perspective view of a flexible member assembly of themedical treatment system of FIG. 9.

FIG. 13 is a perspective view of a distal body of the medical treatmentsystem of FIG. 9.

FIG. 14 is a perspective view of a proximal body of the medicaltreatment system of FIG. 9.

FIGS. 15A-D are side views of the medical treatment system of FIG. 9shown at certain stages of the insertion and deployment of an implant.

FIG. 15E is a cross-section view of the distal assembly of the medicaltreatment system of FIG. 9.

FIGS. 16A-B are side views of alternative controllers of the medicaltreatment system in accordance with the present invention.

FIG. 17 is a side view of an alternative controller of the medicaltreatment system in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The associated drawings and specification discuss aspects and featuresof the present invention in the context of several different embodimentsof implant delivery devices and methods that are configured for use inthe vasculature of a patient. Discussing these features in connectionwith heart valve implants employing stents provides for clarity andconsistency in presenting these inventive features and concepts.However, it is to be understood that the features and concepts discussedherein can be applied to products other than stented heart valveimplant. For example, the controlled positioning, deployment,retraction, and repositioning features described herein can be appliedto medical implants for use elsewhere in the body, such as within thecoronary arteries, the digestive tract, or the like.

In fact, the principles discussed herein can be used in any applicationthat would benefit from a prosthesis delivery device havingrepositioning capability and/or a reduced or negligible radial loadtransferred to the adjacent tissue surface during deployment of theprosthesis. While Applicant specifically provides examples of use ofthese principles in accordance with medical implant delivery devices andspecifically delivery of stents, Applicant contemplates that otherapplications may benefit from this technology.

With reference to FIG. 1, a perspective view of a medical treatmentsystem 100 is shown. The medical treatment system 100 generally includesa controller 102, otherwise referred to as a handle, and a distalassembly 112. The handle 102 includes a barrel 114 with a grip 110located adjacent a proximal end of the barrel 114. The handle 102further includes an actuator 104 located adjacent a distal end of thebarrel. The barrel 114 is affixed to a top most portion of the grip 110.An access to a lumen 106 is provided at the proximal end of the barrel114. The grip and barrel are sized to fit a typical physician's, oruser's, hand to provide a stable grip and operating characteristics.Further, the shape and size of the barrel and grip are ergonomicallyshaped to provide a safe and reliable hold for the user. These featuresof the handle 102 are utilized to control the insertion and deploymentof the distal assembly 112 and successfully implement the medicaltreatment system 100.

The lumen 106 extends through the barrel 114 from the proximal end tothe distal end, terminating at the actuator 104, and providing theoutlet and coupling interface for a flexible portion 116, otherwisereferred to as a proximal catheter. The proximal catheter is coupled tothe handle 102 at a proximal end and is coupled to the distal assembly112 at a distal end, establishing mechanical communication between thehandle and the distal assembly. The actuator, as depicted in theillustrated embodiment, includes a rotating knob 122 that, depending onthe direction of rotation, will longitudinally move elements of theproximal catheter 116 relative the handle. The elements of the proximalcatheter 116 can be moved toward and into, or away and out of, thehandle 102. Alternatively, the proximal catheter can be substantiallyrigid, providing added control to the positioning of the distal assemblyduring the insertion and deployment operations discussed further below.

The distal assembly 112 is coupled to the handle 102 via the proximalcatheter 116, the length of which can vary according to a physician'sneeds. The proximal catheter includes a flexible extension tube 118, asshown in FIG. 3A, and a flexible sheath 120. The flexible sheathincludes a through-hole, or lumen, disposed about a longitudinal axisalong the full length of the sheath. The flexible sheath provides aprotective cover layer over the surface of the flexible extension tube118, yet allows the flexible extension tube 118 to slidingly movelongitudinally within the sheath. The flexible extension tube is acatheter having a lumen disposed about a longitudinal axis. The flexibleextension tube proximal end is engagingly coupled to the actuator 104and handle 102. The flexible sheath proximal end is fixedly attached tothe distal end of the barrel 114 adjacent the actuator 104. The distalend of the flexible sheath is fixedly attached to the distal assembly112. Thus, the length of the flexible sheath establishes the distancebetween the handle 102 and the distal assembly. In alternativeembodiments the flexible extension tube and/or the flexible sheath canbe substantially rigid.

With continued reference to FIG. 1, the illustrated embodiment ofmedical treatment system 100 is generally intended for minimallyinvasive procedures, thus the free length of the proximal catheter 116between the distal assembly 112 and the handle 102 is shorter than ifthe system were primarily directed to a percutaneous procedure to accessa desired location for deployment of the medical implant. However, thefree length of the proximal catheter 116 can be longer, as the medicaltreatment system can be utilized in percutaneous procedures inalternative embodiments of the system.

The lumen 106, in addition to providing an extended path of motion forthe proximal catheter 116 flexible extension tube 118, also provides apath and guideway for an endoscope 108. The endoscope is used to providea physician visual access adjacent to the distal assembly 112 during thedeployment operation of the medical treatment system 100 and is directedthrough the lumen 106 and the flexible extension tube to the distalassembly.

With reference to FIGS. 2A and 2B, a front view of a medical implant200, otherwise referred to as a stent, is shown. In the illustratedembodiment, the implant 200 is configured to allow foreshortening of theframe body upon the longitudinal contraction of the implant 200. Theimplant 200 includes a frame 208, legs 210, otherwise referred to asanchors, a proximal interface 202, a distal interface 204, and anintermediate interface 206. FIGS. 2A and 2B only show a frontside viewof the implant 200 details, omitting the backside structure of thesee-through device for clarity. Additionally, reference to implant 200in further figures is depicted as a simpler cylinder shaped device forclarity and simplicity purposes only.

In a preferred embodiment, the illustrated implant 200 supports a heartvalve body, and can be expanded from a compacted state as shown in FIG.2A to an expanded state as shown in FIG. 2B. The illustrated implant 200preferably is a self-expanding stent constructed of a flexible material,preferably a shape memory material such as nitinol. As the implant isself-expanding, the implant 200 is in a fully opened state, as depictedin FIG. 2B, when relaxed in an unrestrained condition. The illustratedimplant 200 preferably is elongate from a proximal end 212 to a distalend 214 and is tubular with a longitudinal axis 216 and a generallycircular cross section. It is to be understood that in other embodimentsstents can have a non-circular cross section, such as a D-shape, an ovalor an otherwise ovoid cross-sectional shape. In the illustratedembodiment a plurality of spaced apart proximal interfaces 202 areprovided at the proximal end 212 and distal interfaces 204 are providedat the distal end 214 of the implant 200. Other embodiments may beconstructed without proximal or distal interfaces 202, 204.

The illustrated implant 200 has a non-foreshortening portion 218 and aforeshortening portion 220. The portions are joined at a transition 222between the proximal and distal ends 212, 214. Foreshortening refers toa behavior in which the length of the implant 200 in the foreshorteningportion 220 decreases as the radius of the stent increases from thecompacted state to the expanded, deployed state. As such, in FIG. 2A,which shows the implant 200 in a compacted state, the foreshorteningportion 220 of the implant 200 is longer than when the stent is in theexpanded state illustrated in FIG. 2B.

The illustrated implant 200 has a plurality of anchors 210 that extendfrom the transition 222 into the foreshortening portion 220. Additionalanchors 210 also extend from adjacent the distal end 214 into theforeshortening portion. The anchors extending in opposite directionsestablish a gap between their respective free ends, or proximal tip 234and distal tip 236. The longitudinal contraction of the implant createsa corresponding movement of the anchor 210 that moves the proximal anddistal tips closer together. The movement together allows the anchors210 to grasp onto tissues at a desired location so as to hold theimplant in place.

With continued reference to FIG. 2B, the non-foreshortening portion 218of the illustrated implant 200 comprises a plurality of rows or rings226 a-c of circumferentially expansible elements, or struts 224,arranged in a zigzag pattern. The struts 224 are configured to expandand contract with a change in radius of the implant 200. In theillustrated embodiment, the stent has three such rings 226 a-c. It is tobe understood that more or fewer rings can be employed as desired toaccomplish the purposes of this stent frame. In the illustratedembodiment, the respective ends of each circumferential undulating strut224 joins an adjacent strut 224 at an apex 228, 230 which is, in atleast some embodiments, an area of preferential bending. In theillustrated embodiment, the zigzag pattern of a first 226 a and a thirdring 226 c are generally in phase with one another, while the struts 224of a second ring 226 b between the first and third rings 226 a, 226 bare generally out of phase with those of the first and third rings. Itis to be understood that, in other embodiments, all or most of the ringscan be in phase with one another or out of phase as desired.

With continued reference to FIG. 2B, longitudinal struts 232 extendtransversely across the rings 226 a-c of the nonforeshortening portion218 from the proximal end 212 of the implant 200 to the transition 222.More particularly, each ring 226 shares a common longitudinal strut 232.The longitudinal struts 232 extend through apices 228 of adjacent rings226, and preferably extend the entire length of the nonforeshorteningportion 218. Preferably, the longitudinal struts 232 comprise anonexpandable rod or bar. The apices 228 that are connected to thelongitudinal struts 232 are referred to as “connected” apices 228.Apices 230 not connected to longitudinal struts 232 are referred to as“free” apices 230.

As noted above, the longitudinal struts 232 are not substantiallyexpandable in a longitudinal direction. As such, even though theundulating struts 224 provide flexibility in radial expansion orcompaction, as the implant 200 changes radial size between the compactedand expanded states, the longitudinal length of the stent in thenonforeshortening portion 218 remains substantially unchanged.

With reference to FIGS. 3-6, several views of an embodiment of thedistal assembly 112 and its details are shown. The distal assemblyincludes the implant 200 and a delivery device 316. The delivery device316 further includes a proximal mount 300, a distal mount 302, a firstelongate support member 304, a second elongate support member 306, aflanged sleeve 404, a distal collar 406, and a distal body 308. Thedelivery device 316 is used to accurately and safely deliver and deploythe implant, or stent, adjacent a desired location within the patient.

The first elongate support member 304, otherwise referred to as a pullrod or distal catheter, is an elongate member preferably having a degreeof flexibility but maintaining adequate stiffness to be axially loadedin compression and tension. The pull rod 304 includes a lumen extendingalong its full length, similar to a common catheter. The pull rod 304 istypically made of a flexibly capable bio-compatible material for use inthe human body, e.g. silicone, polyurethane, polyethylene,polychloroethene, polytetrafluoroethylene, or the like. The pull rod 304is generally longer and extends distally beyond the distal end of thesecond elongate support member 306. In the illustrated embodiment ofFIG. 4E, the distal end of the pull rod 304 includes an external thread414 for coupling to an atraumatic nose cone or distal body 308, asdiscussed in detail below. The proximal end of the pull rod is coupledto the proximal catheter 116 distal end via the flexible extension 118,also discussed in further detail below.

With continued reference to FIGS. 3-6, the second elongate supportmember 306, otherwise referred to as a proximal stop, is a rigidcylinder having an inner diameter with a diametral magnitude at leastthe same as the pull rod 304, and a support 310 that is integral to thecylinder, as illustrated in FIG. 4A. The proximal stop 306 is typicallymade of a rigid bio-compatible material for use in the human body, e.g.titanium, stainless steel, thermoplastic or thermoset resins, ceramic,or the like. The proximal stop 306 is shorter than the pull rod 306,generally being one to two times longer than the implant 200 althoughother varying lengths are possible. The pull rod 304 is slidinglyengaged within the inner diameter of the proximal stop 306, as describedin detail below, and extends distally out of the distal end of theproximal stop 306 at least ½ to 2 times the longitudinal length of theimplant when the distal assembly is in a longitudinally extendedarrangement, or configuration.

With particular reference to FIG. 6, the proximal mount 300 is a ringshaped device having an interior through-hole disposed about alongitudinal axis, an inner surface, an outer surface, a proximal face,a distal face, at least one guideslot 402, and an annular groove 602.The through-hole establishes the diameter of the inner surface, and theinner surface diameter is substantially the same or slightly greaterthan the outer cylinder surface of a flanged sleeve 404, as depicted inthe illustrated embodiment of FIG. 4. The radial thickness of theproximal mount 300 preferably tapers from a thicker portion at theproximal face to a thinner portion at the distal face. Thus, theproximal face of the proximal mount has a greater surface area,corresponding to the larger wall thickness of the ring member proximalend, as compared to the distal face of the proximal mount 300.

An annular groove 602, depicted in the illustrated embodiment of FIG. 6,is located on the proximal face of the proximal mount 304. The annulargroove 602 extends all around the proximal face, encircling thethrough-hole about the longitudinal axis, and having a depth sufficientenough to receive a proximal ring 506. The guideslot 402 is more clearlydepicted in the illustrated embodiment of FIGS. 4 and 6. The at leastone, or alternatively a plurality of, longitudinal grooves, orguideslots 402, are located on the outer surface of the proximal mount304. The guideslot preferably has a depth that is less than the totalthickness of the proximal mount, and thus does not extend depthwisethrough to the inner surface of the proximal mount 300. The plurality ofguideslots 402 will generally be equally spaced circumferentially aboutthe proximal mount, although any spacing arrangement is possible.

The proximal mount 300 and the distal mount 302 have similar oridentical characteristics that are symmetric about the implant 200, thusin the illustrated embodiment the description of the proximal mountapplies accordingly to the description characteristics of the distalmount except as expressly described. In particular, the through-holes ofthe distal mount 302 and the proximal mount 304 can be different indiametral size where they are coupled to differing sized mountingelements, such as the diameter of the neck on the distal body 308, withwhich the distal mount is coupled, or the flanged sleeve 404, with whichthe proximal mount 300 is coupled, as described in detail below.

With continued reference to FIGS. 4A, 4D and 4F, an embodiment of theflanged sleeve 404 and the distal collar 406 are shown. The flangedsleeve 404 is a substantially cylindrical member having a flange, orlip, portion protruding radially outward from the outer surface of thecylinder and located adjacent the distal end of the flanged sleeve 404.The inner surface of the flanged sleeve 404 establishes a through-holedisposed about a longitudinal axis. The diameter of the through-hole issubstantially the same as, or slightly greater than, the outer surfacediameter of the proximal stop 306. The outer surface diameter of theproximal flanged sleeve cylindrical portion is substantially the same,or slightly less than, the inner surface diameter of the proximal mount300. The cylindrical body of the flanged sleeve 404 extends alongitudinal length that is longer than the longitudinal length of theproximal mount 300.

In the illustrated embodiment, the distal collar 406 is a ring, similarto a washer or a nut, having a through-hole disposed about alongitudinal axis. The longitudinal thickness of the collar 406 issufficient to include internal fastener threads on the inner surfacediameter of the through-hole. The hole is sized substantially the sameas pull rod 304. The collar 406 is made from a rigid, bio-compatiblematerial, e.g. metal, plastic, Teflon, or the like. Alternatively, thecollar can be fabricated from a flexible member that deflects radiallyoutward further than a rigid collar yet sufficiently capable ofretaining the distal mount on the nose cone, e.g. a radial spring, anelastic material such as rubber, or the like.

The distal body 308, otherwise referred to as a nose cone, as best shownin FIGS. 3 and 4, is generally a cone or frustum shaped, bullet nosedstructure with bulbous rounded surfaces to advantageously provide anatraumatic gentle entry and movement within the patient's vasculatureand mitigate the risk of injury to adjacent tissue due to the insertionof the distal assembly 112 within the patient. The cone shaped structureof the nose cone 308 is disposed about a longitudinal axis, with thelarger diameter base of the cone located adjacent a proximal end of thenose cone 308 and the decreasing, tapering, or arcing, diameter extendsto a generously rounded distal end, or tip, of the nose cone 308.

With continued reference to FIGS. 4A-B, the nose cone 308 includes athrough-hole disposed about the longitudinal axis along the full lengthfrom the proximal end to the distal end. The through-hole diameter issimilar in magnitude to the inner diameter of the pull rod 304. The nosecone 308 proximal end, or proximal face 416, also includes a flange 408and a neck 410 that extend proximally from the proximal end of the cone308, and are substantially centrally disposed about the longitudinalaxis of the nose cone 308. The flange has a diameter smaller than thecone but larger than the neck. The flange extends proximally asufficient amount to create a shallow lip, such that a small gap existswhen the distal mount is installed on the neck 410, as described indetail below. The neck extends even further proximally, establishing aproximally protruding cylinder off of the nose cone 308. The neck has asmaller outer diameter than the flange and also includes internalfastener threads adjacent the proximal end.

The through-hole of the nose cone 308 provides an access point for theendoscope 108, allowing the endoscope to pass through and exit out ofthe distal end, after which the endoscope 108 can then look backproximally on the distal assembly 112 and the implant 200 to providevisualization of the deployment process. An alternative embodiment ofthe nose cone 308 includes an internal configuration providing anarcuate path, within the cone 308 itself, and exiting for example out ofthe side of the cone 308. Such a configuration routes the endoscope 108viewing tip back toward the implant prior to exiting the distal end ofthe nose cone 308, placing the viewing tip nearer the implant. Theendoscope 108 can similarly exit any surface of the cone 308 that issufficient to provide a visualization of the implant. In furtherembodiments, an aperture or viewing port can be formed in the pull rod304 to enable an endoscope 108 to view the implant.

With reference to FIGS. 3 and 4A, the side view of delivery device 316further shows an embodiment of the support 310. The support 310 is anintegral lip extending all around the proximal stop 306 and locatedadjacent the proximal end of the proximal stop 306. The support 310 hasa substantially flat surface on the distal face, the face also beingsubstantially normal to the longitudinal axis of the proximal stop 306.The proximal face of the support 310 has a tapered surface extendingfrom the radially outermost surface, or diameter, of the support 310 tothe outer surface of the proximal stop 306 cylindrical surface. As willbe discussed below, the support 310 provides a physical stop and supportfor the proximal mount 300 disposed about the proximal stop 306,preventing the proximal mount from sliding or moving too far proximallyas well as locating the proximal mount for installation of implant 200onto delivery device 316.

With continued reference to FIG. 3, the side view of delivery device 316further shows the proximal flexible member 312, otherwise referred to asa proximal suture, and the distal flexible member 314, referred to as adistal suture. In the illustrated embodiment, the sutures 312, 314attach the implant/stent 200 to the delivery device 316. The length ofthe sutures 312, 314 can vary according to the size and location of thestent 200 and the delivery device 316. The diameter of the sutures 312,314 can vary as well, provided the sutures 312, 314 can sustain thetensile loads required for the implant installation and deploymentprocess. The sutures 312, 314 preferably are made of typicalbio-compatible suture materials, e.g. nylon, polypropylene, polyglycolicacid, polyethylene, other thermoplastic polymers, cotton, silk, or thelike. As will be discussed below, a plurality of sutures 312, 314 areused to attach the implant to the delivery device 316, as attachment ismade at both the proximal and distal ends of the implant and the implantpreferably is substantially centered about the delivery device 316. Inalternative embodiments the flexible members can have differingconfiguration, can be made of other materials, and may be substantiallyrigid.

With reference to FIGS. 5 and 6, a perspective view of selected detailsof the distal assembly 112 are shown, which includes a proximal ring506, a distal ring 508, the proximal interface 202, and the distalinterface 204, the anchor 210, and an annular groove 602. The proximalring 506 and the distal ring 508, otherwise referred to as proximal snapring and distal snap ring, respectively, have similar characteristics inthe illustrated embodiment; thus the description of features applies toboth elements unless expressly described otherwise. The proximal ring506 is made of a small diameter member, generally a rigid bio-compatiblematerial, e.g. metal, plastic, or the like, that is shaped to form acircle, where the circle generally lies on a common flat plane.

The small diameter member is formed in a circular manner such that thetwo ends of the member are adjacent each other, resulting in a slightgap between the ends. The proximal ring 506 has a through-hole,establishing an inner diameter that is greater than the outer diameterof the cylindrical body of the flanged sleeve 404. The diameter of thesmall diameter member is less than the wall thickness of the proximalend of the proximal mount 300. As will be discussed in detail below, thegap between the ends of the member provides access for the sutures 312connection to the ring and subsequently to the delivery device 316.Alternatively, there is no gap in the ring, creating a continuouscircle, whereby the sutures are individually tied onto the rings, orjust folded over the ring and press fit into the annular groove, asdiscussed in further detail below, at the same time as the ring.

With continued reference to FIGS. 5 and 6, an embodiment of the implant200 includes a plurality of the proximal interface 202 and the distalinterface 204, as shown. The proximal interface 202 establishes aconnection, or attachment, location for the suture 312 and the distalinterface 204 establishes an attachment location for the suture 314.Thus the proximal interface 202 and distal interface 204, in combinationwith the sutures 312, 314, connect the implant to the delivery device316. The shape and location of the interfaces 202, 204 can varyaccording to a physician's particular needs, and their shapes are notrequired to be identical, although such a configuration is possible.Their shape can be any three-dimensional geometry providing connectioncapability to the suture 312, e.g. an eyelet as shown, a hook, aradiused or sharp angled triangle element, a block, a sphere, a t-shapedleg, or the like, and any combination thereof. Additionally, the suturecontacting surfaces of the interfaces 202, 204 can vary as well, e.g.smooth, grooved, random discontinuous roughness, or the like, and anycombination thereof. Alternatively, the interfaces can be locatedanywhere on the implant instead of at the proximal and distal endsprovided sufficient tension on the implant 200 can be achieved to obtaina reduced diametral cross-section of the implant, as discussed in detailbelow. For example, in one embodiment an intermediate interface 206 isprovided just proximal the foreshortening portion. In one suchembodiment, proximal sutures connect to the intermediate interface,extend along the non-foreshortening portion and through the proximalinterface, and then to the proximal mount 300.

With continued reference to FIG. 5, the illustrated embodiment of theimplant 200 has a plurality of anchors 210 for grasping the tissues ofthe vasculature at a desired location to hold the implant in place, asdescribed in detail above. Alternatively, other embodiments for otheruses may not have anchors.

The above described individual details will now be described withrespect to their assembled arrangement and configuration to comprise themedical implant system. Distal assembly 112 is assembled to providehandle 102 controlled longitudinal displacement of the pull rod 304 andthe nose cone 308. The pull rod and the nose cone are rigidly coupledtogether and share a substantially common longitudinal axis extendingthrough their respective through-holes, or lumens. The coupling isachieved by way of the external thread 414 on the distal end of the pullrod 304, which threadingly engage the inner surface of the nose cone 308through-hole, which includes a corresponding internal thread featureadjacent the nose cone proximal end.

With continued reference to FIGS. 3 and 4A, the nose cone 308, prior tobeing coupled to the pull rod 304, is first coupled to the distal mount302. The distal mount 304 through-hole is received on the nose cone 308neck that protrudes proximally. The distal face of the distal mount 304,having the increased cylinder wall thickness, is abutted against theflat surface of the nose cone flange, which is orthogonal to thelongitudinal axis of the neck, nose cone and distal mount 304, all ofwhich are substantially co-axial. The distal mount 304 is coupled viafriction, where the diameters of the neck and the through-hole aresufficiently closely toleranced that a press fit occurs between the twodetails.

Alternatively, or additionally, the distal mount 304 may be held inplace by a distal collar 406, which is a ring or washer havingsufficient thickness to be threaded on the inner surfaces of athrough-hole extending along a longitudinal axis. The through-hole issized to threadingly engage the pull rod 304 external thread 414. Thus,in the illustrated embodiment the distal mount 304 would be threadinglypressed between the distal collar 406 and the nose cone 308 flange asthe external threads of the pull rod engage both the nose cone 308 andthe distal collar. Alternatively, the distal collar 406 can befrictionally press fit on the distal end of pull rod 304 to abut theproximal face of the distal mount 304. Thus, the distal mount 304 ispressed between the nose cone 308 and the distal collar 406 by press fitfriction and thread engagement, either alone or in combination.

In the embodiment shown in FIGS. 3 and 4, the flanged sleeve 404 isconfigured to secure the proximal mount 300 onto the proximal stop 306.In one sequence, the proximal mount 300 is first inserted onto theflanged sleeve 404, then the flanged sleeve 404 is inserted onto theproximal stop 306. Further details of the insertion steps are such thatthe through-hole of the proximal mount 300 is sized to fit snugly ontothe cylindrical body of the flanged sleeve 404. The proximal mount isinitially inserted onto the proximal end of the sleeve 404 and sliddistally until the distal face of the proximal mount abuts the radiallyoutward protruding lip 412 of the sleeve 404. The through-hole of theflanged sleeve 404 is sized to fit snugly, via friction of the twomating surfaces, onto the elongate cylinder surface of the proximal stop306. Alternatively, the proximal mount and the flanged sleeve can be anintegral single-piece detail that achieves the described features andfunctions, eliminating the need for friction between the two details.

The sleeve 404 is then inserted onto the proximal stop 306 distal endand slidingly displaced proximally along the cylinder length toward thesupport 310. A gap ‘A’ exists between the proximal face of the proximalmount, where gap ‘A’, as shown in FIG. 3B, is established by the longerlength accorded to the cylinder of the flanged sleeve 404 as compared tothe longitudinal length of the proximal mount 300. Therefore, in theillustrated embodiment of FIG. 3B, a proximal mount 300 moved all theway distally against the lip of the sleeve 404 will result in theproximal end of the flanged sleeve 404 creating the gap ‘A’ betweensupport 310 and mount 300.

The pull rod 304 proximal end is coupled to the distal end of theflexible extension tube 118 of the proximal catheter 116, establishinglongitudinal displacement capability and communication between the pullrod 306 and the handle 102. The displacement capability is via theactuator 104, because the flexible extension tube 118 of the proximalcatheter 116 proximal end is coupled to the actuator 104, the actuator104 is located at the distal end of the handle 102, and actuating theactuator pushes the flexible extension tube 118 of the proximal catheterlongitudinally. The pull rod 304 proximal end terminates at the couplingto the flexible extension tube 118 of the proximal catheter 116 in thegeneral area adjacent the proximal stop 306 proximal end when thedelivery device 316 is assembled. Thus the pull rod 304 and the flexibleextension tube 118 of the proximal catheter 116 extend through andslidingly engage within the proximal stop 306, however the pull rod 304consumes the majority of the longitudinal length within the proximalstop 306 when the stop and the pull rod are in the un-extendedlongitudinal state, as shown in FIGS. 3A, 3B, and 4A. Such aconfiguration advantageously establishes a level of stiffness betweenthe proximal mount 300 and the distal mount 302 that are affixed to theproximal stop 306 and the pull rod 304, respectively, the portion of thedelivery device that locates and deploys the implant 200. Alternatively,the respective lengths, endpoints and connect locations between theproximal stop 306 and the pull rod 304 can vary such that the couplingdoes not occur adjacent the proximal stop proximal end, providedsufficient control of the implant 200 is achieved.

In an assembled configuration of the illustrated embodiment of FIGS. 3Aand 3B of the delivery device 316, prior to installation of the implant200, the proximal stop is not free to slide over the coupled flexibleextension tube 118 and pull rod 306. The flexible sheath 120, thatcovers and protects the flexible extension tube 118 and is fixedlyattached to the handle 102 at the proximal end of the sheath 120, isabutted and/or coupled to the proximal end of the proximal stop 306 atthe opposing distal end of the sheath 120. Thus the proximal stop 306,the proximal mount 300, the flexible sheath 120, and the handle 102 arecoupled together, effectively functioning as a single member in theassembled state, with the proximal stop 306 being a stiffer relativeportion of the effective member as compared to the flexible sheath 120.All through-holes and inner diameters share substantially coincidentlongitudinal axes.

Similarly, in the assembled state, the nose cone 308, the distal mount302, the pull rod 304, and the flexible extension tube 118 are coupledtogether, also effectively functioning as a single member. Thus, thepull rod 304 is a stiffer relative portion of the effective member ascompared to the flexible extension tube 118. All through-holes and innerdiameters share substantially coincident longitudinal axes. Theeffective single member comprising the pull rod 304 is the movingelement, that moves relative the static proximal stop 306 effectivemember. The noted movement is controlled by the actuator 104, byproximally and distally moving the nose cone 308, the distal mount 302,and the pull rod 304 through interaction with the flexible extensiontube 118.

The pull rod 304 and its effective member is in longitudinally movablecommunication with the handle 102, and is located within, and thus moveswithin, the through-hole inner diameter of the proximal stop 306 and itseffective member. The actuator 104 moves the pull rod 304 longitudinallyrelative the proximal stop 306 and its effective member of the handle102, the flexible sheath 120, the proximal stop 306, and the proximalmount 300. The pull rod 304 and the proximal stop 306 share the samelongitudinal axis, their respective axes being substantially coincident.Thus, the two effective members move relative each other. In theillustrated embodiment, the pull rod 304 extends through the proximalstop 306 and the relative longitudinal motion is between the outerdiameter surface of the pull rod 304 and the inner diameter surface ofthe proximal stop 306.

The increased stiffness of the proximal stop 306 and the pull rod 304provides structural support to the distal assembly 112 thatadvantageously provides control during positioning and adjustment of theimplant, as well as stability during any relative longitudinal motionbetween the proximal mount 300 and the distal mount 302.

With reference again to FIG. 1, in the illustrated embodiment, theactuator 104 is coupled to the flexible extension tube 118, andactuation means occurs when the rotating knob 122 is rotated about theaxis of the barrel 114, and the lumen 106. The actuation means can beany mechanical or electromechanical method known in the art, e.g. threadengagement, spring and detent, worm drive, or the like. It is understoodalso that, in other embodiments, the actuator 104 can be configureddifferently in the controller 102, such as being a trigger or the like.

The above described details are combined and configured to provide adistal assembly 112 that readily positions, and is capable of readilyrepositioning, a medical implant at a desired location within a patient.

The distal assembly 112 advantageously provides for insertion,deployment and repositioning of the implant 200 without requiringexternal radial or longitudinal deployment forces that carry the risk ofharming the tissue of and adjacent to the desired deployment location.

The stent 200 is temporarily secured by coupling means to the deliverydevice 316 for the insertion and deployment process, after which, whenthe implant is located as desired, the stent 200 is then removed fromthe delivery device 316. The removal, or release of the coupling means,and the diameter of the delivery device allows the delivery device to bebacked out of the insertion location safely, without harming thevascular tissue through which it passed to gain access to the desiredlocation.

The delivery device 316 has the implant installed, as illustrated inFIGS. 3, 5, and 6 to establish a distal assembly 112 that is fullyprepared for delivery and deployment within the patient's vasculature.The installation of implant 200 utilizes the proximal interface 202, theproximal sutures 312, and the proximal ring 506 on the proximal side ofthe implant. Similarly, on the distal side of the implant, installationutilizes the distal interface 204, the distal sutures 314, and thedistal ring 508. The installation sequence for the proximal and distalends of the implant 200 are identical, thus the description of theproximal end installation accordingly applies to the distal end of theimplant 200.

With particular reference to FIG. 4, the installation of the proximalend of implant 200 entails coupling the plurality of proximal sutures312 to the proximal interface 202 and the proximal mount 300. Theconnection to the proximal mount 300 occurs via a loop or a knot tied tothe proximal ring 506, after which the proximal ring 506 is placed inthe annular groove 602 and the suture is aligned in the guideslot 402 tocomplete the attachment. The proximal suture 312 may be individuallytied by a knot at each of the proximal interface 202 and the proximalmount, or can be looped through both with a single knot tying both endsof the suture together. Variation can exist in where the individualknots are tied after individually looping the suture 312 through theproximal interface 202 and the proximal mount.

Advantageously, a knot can be placed adjacent the proximal mount 300 andthe suture 312 simply looped through the proximal interface 202. Thisallows for a single cut of the suture to be made that releases theimplant without leaving suture material attached to the implant, butensures the suture 312 remains attached to the proximal mount uponremoval of the delivery device 316 from the patient's vasculature.

With particular reference to FIG. 3, at least two, and preferablyseveral, proximal sutures are used to couple the proximal end of theimplant 200 to the proximal mount 300, sufficiently spaced apartcircumferentially about the longitudinal axis of the delivery device 316such that the implant 200 is substantially centered about the axis. FIG.3 illustrates the implant installed on the delivery device 316 in alongitudinally unrestrained condition, such that the diameter of theimplant is at its self-expanding maximum.

The above described details are combined and configured to provide adistal assembly 112 that readily positions, and is capable of readilyrepositioning, a medical implant at a desired location within a patient.The insertion and deployment sequence, as illustrated in FIGS. 7A-C and8A-D, is described below.

Once the implant is attached to the proximal and distal mounts, as shownin FIG. 3A, the actuator 104 is actuated to extend, or displaceoutwardly from handle 102, the flexible extension tube 118. The outwarddistal displacement is transmitted from the flexible extension tube 118to the pull rod 304 and the distal mount 302.

This distal displacement of the distal mount 302 lengthens the deliverydevice 316 distance between the proximal mount 300 and the distal mount302 which results in a longitudinal tension on the proximal and distalflexible members 312, 314 and thus, the implant 200. The longitudinaltension applied to implant, as described above, extends the longitudinallength and contracts the diameter of the implant 200 to a compactedstate, as shown in FIG. 7A. To minimize the contracted diameter of theimplant, preferably the guideslots 402 are smaller than the diameter ofthe nose cone. This allows the sutures 312, 314 to be stretched intension parallel to the longitudinal axis, which would result in adiameter of implant that approximates that of the sutures 312, 314.

The distal assembly 112 is then inserted, preferably in a minimallyinvasive manner, into the patient and the endo scope 108 is optionallyinserted through the lumen 106, the flexible extension tube 118, thepull rod 304, and the nose cone 308 to provide visualization assistanceduring the positioning and deployment procedure. The distal assembly isinserted into the vasculature and directed toward the desired location702, which is the native annulus of the heart valve as illustrated inFIGS. 7A-B.

The implant 200 legs 210 are then centered about the desired location702, as illustrated in FIG. 7B, whereupon the actuator 104 is actuatedto retract the flexible extension tube 118, which moves the distal mount302 proximally toward the handle 102. This longitudinal shortening ofthe delivery device 316 between the proximal mount 300 and the distalmount 302 allows the longitudinal length of the implant 200 to contractand the diameter of the implant to expand under the self-expandingproperties of the implant. Thus, as described above, the foreshorteningportion of the implant is contracted and the legs 210 are drawn closertogether so as to grasp the heart valve native annulus 702, asillustrated in FIG. 7C.

In a preferred embodiment, after initial deployment the clinicianverifies whether the implant has been properly positioned. In oneembodiment, position is verified by using the endoscope as discussedabove. Should repositioning be desired, the clinician actuates theactuator 104 to extend the distal mount 302 and pull rod 304 such thatthe implant again extends longitudinally and contracts diametrally, andas a result, disengages from its improperly positioned state.

When the implant 200 is safely disengaged, the deployment process can berepeated after repositioning the implant 200 into an adjusted, desiredlocation 702. The delivery device 316 allows for the above describedsequence of position, engage, and disengage, to be repeated until theimplant 200 is properly positioned. It is to be understood that whilemaking such adjustments, it may be sufficient to only partially radiallycontract the implant.

With reference to FIGS. 8A-D, after the implant 200 is verified asproperly positioned, the delivery device 316 is removed from the implantand the patient's vasculature. The removal sequence is initiated bysevering the proximal sutures 312 as described above, leaving thetotality of the sutures secured to the proximal mount 300 and ensuringno part of the sutures remain either free within the vasculature orattached to the implant 200 proximal interface 202. In a minimallyinvasive procedure, preferably the clinician can access, cut, and removethe proximal sutures while the delivery device remains in place. FIG. 8Aillustrates the proximal sutures severed, with the proximal sutures notshown for clarity. In another embodiment, the delivery device may have astructure for detaching the sutures from the implant, yet retains thesutures so that they are removed from the patient with the device.

Severing of all the proximal sutures 312 allows partial retraction ofthe delivery device 316 by actuating the actuator 104 to retract thepull rod 304 in the proximal direction, bringing the distal mount 302adjacent the proximal stop 300. In combination with the retraction ofthe pull rod 304, the entire system, except for the implant 200, can bemoved proximally to further back the delivery device out of the interiorof the implant 200. The delivery device can not be fully removed yet,however, because the distal sutures remain attached to the implant 200.The distal mounts are retracted proximally a sufficient distancerelative the implant 200, as illustrated in FIG. 8B, to allow sufficientclearance and access to the distal sutures 314 so they can be cutwithout necessitating entry of the cutting device into the interior ofthe implant 200.

With continued reference to FIGS. 8A-D, such a sequence dictates apreferred sizing of the pull rod 304 whereby the longitudinal length ofthe pull rod 304 is sufficiently long enough that at full extension twopreferred conditions are met. First, that there is sufficient internaloverlap between the pull rod 306 and the proximate stop 304 such thatadequate stiffness to maintain positioning control of the deliverydevice exists. Second, that the longitudinal length of the distal suture314 is approximately at least as long as, and more preferably, 1¼ timesas long as, the longitudinal length of the vasculature installed, orunrestrained, implant. The second condition ensures that the distalmount can move to a position so that severing of the distal sutures 314can be performed without the cutting device entering the implant.Alternatively, the sutures 312, 314 can be configured such that thesutures are disconnected from the implant by other structures andmethods, such as the sutures disengaging by other mechanical action fromthe implant 200, knots being untied rather than severed, or the like.After the distal sutures 314 are severed, the delivery device 316 isfree to move as a complete system proximally out of the vasculature andthe patient, as illustrated in FIGS. 8C-D.

With reference to FIGS. 9-15, another embodiment of a distal assembly isdisclosed. The disclosed embodiment uses spring mechanisms inconjunction with the handle 102 to control the deployment of the implant200. The spring mechanisms include a proximal spring 918, a distalspring 920, and an intermediate spring 916. The proximal and distalsprings 918, 920 are preferably helical compression springs,substantially similar in spring constant, diameter and longitudinallength. Intermediate spring 916 is preferably a helical compressionspring, similar in diameter to springs 918, 920 but has a springconstant that is less than that of proximal and distal springs 918, 920,thus requiring less compressive or tensile forces to compress or stretchthe spring 920.

The illustrated embodiment further includes a first elongate supportmember 902 and a second elongate support member 904 that togethercontrol the longitudinal motion and displacement of the delivery deviceduring the insertion and deployment of implant 200. The first elongatesupport member 902, otherwise referred to as a mount tube, is a rigidtube having a distal mount 1002 fixedly attached to the distal end ofthe mount tube 902. The illustrated embodiment of the second elongatesupport member 904, otherwise referred to as a pull rod, is a rigid tubein mechanical communication with a controller device such as handle 102in a similar fashion as described above for distal assembly 112. Thepull rod 904 has an outer surface diameter such that the pull rod 904fits inside of the mount tube 902 and can slidingly engage the mounttube inner diameter.

With reference to FIG. 10, the distal mount 1002, typically integrallyor fixedly attached to the distal end of the mount tube 1002, has agenerally cylindrical shape that is coincident with the mount tube 902.The distal mount 1002 includes at least one guideslot 1004, which islocated on a proximal lip 1006, a groove 1008 that is disposedcircumferentially about the distal mount 1002, and a distal lip 1010located at the distal end of the mount tube 902. The groove 1008 isfurther established by and located between the proximal lip 1006 and thedistal lip 1010. The guideslot 1004 extends longitudinally on theproximal lip 1006.

With continued reference to FIGS. 9 and 11, the illustrated embodimentfurther includes a proximal mount 906, a proximal body 912, a distalbody 914, a proximal flexible member 908, and a distal flexible member910. The proximal mount 906, illustrated in detail in FIG. 11, includesa proximal lip 1104, a groove 1102 that is disposed circumferentiallyabout the proximal mount 906, a distal lip 1106, and at least oneguideslot 1108. The proximal mount 906 is configured in a similararrangement as the distal mount 1002 except the proximal mount 906includes a through-hole having a longitudinal axis that is sized toslidingly engage the outer surface diameter of the mount tube 902.Additionally, the proximal mount is symmetrically reversedlongitudinally relative to the distal mount 1002, such that, forexample, the guideslots are located on the distal end of the proximalmount 906.

The proximal flexible member 908, and the distal flexible member 910 areidentical, comprised of a flexible member assembly 1200 as illustratedin FIG. 12, but symmetrically opposed on their common longitudinal axisabout the implant 200 in the assembled arrangement. The flexible member1200 includes a plurality of arms 1202, and a ring 1204. The arms 1202are J-shaped wire-type elements, where the elongate portion is coupledto the ring 1204 and the radiused portion is biased to flare radiallyoutward when the arms 1202 are in an unrestrained condition. The ring1204 has a longitudinal length and an inner and outer diameter that isconfigured to mate with the grooves 1102 and 1008 on the respectivemounts. The flexible member assembly 1200 preferably is comprised of asemi-rigid, or resiliently flexible material, e.g. metal, plastic, orthe like. In alternative embodiments the flexible members can besubstantially rigid and still provide the longitudinal tension requiredas described below.

The proximal body 912, as illustrated in the embodiment of FIG. 14,includes two cylindrical portions, a smaller diameter cylinder sized toslidingly engage the mount tube 902 and the larger diameter cylindersized to receive the proximal spring 918 and the proximal mount 906. Thedistal body 914, as illustrated in FIG. 13 includes a head 1300 having aconical shape similar to the nose cone 308 and a cylindrical body sizedand configured to receive the distal spring 920 and the distal mount1002.

The implant 200 preferably includes proximal and distal interfaces 202,204 as described above.

The distal end of the pull rod 904 is coupled to the head 1300 of thedistal body 914, within the through-hole lumen that is disposed aboutthe longitudinal axis of the head 1300. The distal spring 920 isdisposed about the pull rod 904 and located between head 1300 and thedistal mount 1002 within the cylindrical portion of the distal body 914.

Prior to coupling the distal body 914 to the pull rod 904 in theillustrated embodiment, the remaining details are assembled on the pullrod 904 as follows. The mount tube 902 has several details installedover the cylindrical tube. Intermediate spring 916 is inserted on theproximal end of the mount tube 902 distally until contacting theproximal end of the distal mount 1002. Next, the distal end of theproximal mount 906 is placed onto the mount tube 902 and the mount 906is slidingly engaged distally until contacting the proximal end of theintermediate spring 916.

With particular reference to FIG. 9, the proximal spring 918 is theninserted in a like manner, followed by the larger diameter distal end ofthe proximal body 912. The distal end of the proximal body 912 isinserted on the mount tube 902 until an inner orthogonal flat surface,which transitions the larger cylinder to the smaller cylinder of thebody 912, contacts the proximal end of the proximal spring 918. Theflexible sheath 120 is then coupled to the proximal end of the proximalbody 912, to establish a fixed distance between the proximal body andthe controller 102. The proximal and distal mounts 906, 1002 will alsohave the proximal and distal flexible members 908, 910 installed ontothe respective mounts, such that the J-shaped arms are oriented tocouple to the implant 200 at the proximal and distal interfaces 202,204. The distal spring 920 is then placed over the pull rod distal end,and finally the distal body 914 is coupled to the pull rod distal end.

Thus, when the implant 200 is coupled to the proximal and distalflexible members 908, 910 the proximal mount 906 is effectively coupledto the distal mount 1002 via the distal flexible members 908, 910 andthe implant 200, with the intermediate spring 916 located between thetwo mounts 906 and 1002. The intermediate spring 916 urges the mountslongitudinally apart, which supplies tension to retain the implant 200in a longitudinally extended and diametrally contracted configuration asshown.

With continued reference to FIG. 9, for the distal assembly 900, theflexible sheath 120, not shown, as described above, abuts the proximalend of the proximal body 912. Preferably, and as discussed above,longitudinal displacement of the pull rod 904 due to extraction orcontraction via actuating of the actuator 104 occurs within the flexiblesheath 120. Thus, the mount tube 902 and the aforementioned installeddetails on the mount tube 902 essentially float between the nose cone1300 and the flexible sheath 120. This floating condition allows foroperation of the delivery device 900 to insert and deploy the implant200. The proximal body 912 is prevented from moving toward the handle102 by the sheath 120.

The implant 200 installation on the delivery device 900 completes theassembly of the distal assembly 900, which is achieved as follows. Theintermediate spring 916 is compressed to hold the proximal and distalmounts close enough together to allow the arms 1202 to be coupled to theproximal and distal interfaces 202, 204 of the unrestrainedself-expanded implant. Alternatively the implant 200 can belongitudinally extended in tension prior to the coupling to the flexiblemembers to allow the interfaces to complete the coupling, or furtherstill there can be a combination of the two, compression of intermediatespring 916 and longitudinal tensile extension of implant. Once coupled,the intermediate spring is released and allowed to expand, extending theimplant longitudinally, as the spring constant is chosen to besufficient to overcome any resistance in the self-expanding implant tosuch longitudinal extension.

With reference to FIGS. 15A-E, the method of operation of the distalassembly will be described. More specifically, once the implant 200 isloaded, the delivery device is initially in the compacted state shown inFIG. 15A. The pull rod 904 distal end is coupled to the distal body 914and the pull rod 904 proximal end is coupled to the actuator 104. Theactuator 104 is configured to move the pull rod 904 toward the handle102 when actuated, so as to pull the distal body 914 toward the handle102. This relative movement between the distal body 914 and proximalbody 912 is resisted by each of the distal spring 920, proximal spring918, and intermediate spring 916. However, because the intermediatespring 916 has a lower spring constant, the intermediate spring 916 willcontract first before either the proximal or distal springs 918, 920.

Contraction of the intermediate spring 916 allows the implant 200 tocontract longitudinally and expand diametrally because the mounts 906,1002 move closer to each other. As the mounts contract and the implantself-expands diametrally, the arms 1202 on the flexible members 906, 910remain coupled to the implant. Thus, in use, once the distal assembly isproperly positioned, the actuator 104 is actuated to begin thelongitudinal contraction and engaging of the adjacent surfaces of thedesired location 702 as described above, and as depicted in FIG. 15B. Ina similar reverse method, the distal assembly can be disengaged andrepositioned as discussed above.

Upon successful deployment of the implant 200 the delivery device 900 isnext removed from the implant by releasing the arms 1202 and extractingthe delivery device. With particular reference next to FIG. 15C, removaloccurs by further actuation of the actuator 104 in a manner that movesthe pull rod 904 distally away from the handle 102 and concurrentlymoves the distal body proximally toward the handle 102. The intermediatespring 916 will eventually bottom out in compression and stopcontracting. As the actuator continues to move the pull rod 904proximally, the higher spring constant proximal and distal springs 918,920, which did not contract previously because the spring constant ishigher than the intermediate spring 916, will then contract under thecontinued compressive forces created by the distal motion of theactuator 104. Preferably, one or more physical stops are disposed on themount tube 902 to stop further compression of the intermediate spring.

With continued reference to FIG. 15C, as the springs 918, 920 compress,the distal body 914 and the proximal body 912 move toward the implantand the cylindrical bodies adjacent the implant 200 encompass the arms1202 of the proximal and distal flexible members 908, 910. The motion,combined with movement of the flexible member 908, 910 toward the centerof the implant 200, of the cylindrical bodies encompassing the arms 1202draws the arms radially inward toward the longitudinal axis, to beparallel to the inner diameter surface of the bodies. This motion bringsthe j-shaped radiused ends of the arms 1202 out of the proximal anddistal interfaces 202, 204 of the implant. With additional reference toFIGS. 15D and 15E, the distal assembly is now free to be withdrawn fromthe interior of the implant and the patient's vasculature system.Notably, the lumen extending through the delivery device 900 is notshown in the cross-section view of FIG. 15E for clarity. In anotherembodiment, the delivery device includes a detent preventing movement ofthe pull rod 904 proximally to release the arms 1202. Once the clinicianhas verified the correct positioning of the implant 200, the detent maybe actuated to allow further movement of the pull rod 904.

With reference to FIGS. 16A-B and 17, various embodiments of the handle102 are shown. FIG. 16A depicts one embodiment of a handle having anactuator 104 driven by rotation of an actuator knob 122. Rotation of theknob 122 engages the flexible extension tube 118 of the proximalcatheter 116 so as to longitudinally displace pull rod either proximallyor distally, depending on the rotation direction of the knob. Theengagement can be applied by various methods, such as rotation ofthreads or the like. A lever 1600 is optionally included and provides asecondary stop mechanism, such as a detent, that prevents actuation ofthe flexible extension tube 118 of the proximal catheter unless thelever 1600 is biased against the grip 110, which releases the detentstop mechanism and allows actuation of the proximal catheter.

With further reference to FIG. 16B, a lever and spring loaded embodimentis shown to provide longitudinal displacement capability for the handle102. The handle 102, as illustrated, includes a lever 1600, and actuatorspring 1602, and a locking mechanism 1604. The lever 1600 extendsdownward from the distal side of the grip 110. This orientation allows auser to hold the grip 110 and concurrently actuate the lever proximallyand distally about the connection pivot point that is located at the topof the grip 110 adjacent the barrel 114. The spring 1602 is disposedwithin the barrel about the outer diameter surface of the lumen 106 andthe proximal catheter 116.

With continued reference to FIG. 16B, the proximal end of the spring1602 is coupled to the top end of the lever 1600 and the distal end ofthe spring 1602 is coupled to the distal end of the handle 102 or thebarrel 114. The spring is located in a compressed configuration,imparting a tensile force on the handle 102 and the lever 1602. Thetensile force of the spring 1602 biases the lever in a distal directionabout its pivot connection to the handle 102. The locking mechanism 1604applies a friction force to the flexible extension tube 118 of theproximal catheter 116 preventing longitudinal displacement. In oneembodiment, the lever 1600 moves the catheter and the spring 1602 biasesthe lever 1600 to the closed position, which is away from the grip 110,as shown in FIG. 16B. Actuation occurs when the lever 1600 is pulledtoward the grip 110 and the lever pushes the proximal catheter distally,so as to also push the pull rod distally. Lock 1604 then holds theproximal catheter in place. In another embodiment, the sequence can bereversed, such as for the spring driven delivery device 900, such thatactuation of the lever 1600 pulls on the flexible extension tube 118 ofthe proximal catheter to deploy the implant. In one embodiment, the lock1604 can be configured to actuate a detent that prevents advancement orretraction beyond a specified distance, and the detent can be disengagedupon manipulation of the lock 1604.

With reference to FIG. 17, an alternative embodiment of controller 1700,otherwise referred to as a handle, is shown. The handle 1700 includes aknob 1702, a grip 1704, a dual spring 1708, and an actuator 1706. Theknob 1702 is coupled to a longitudinal neck that is further coupled tothe flexible extension tube 118 of the proximal catheter 116. The knob1702 rests in the palm of the user, or physician. The grip 1704 includesat least one radially extending arm that is held by the users fingers.The actuator 1706 extends radially and is actuated by the users thumb.The actuation of the actuator 1706 engages the spring 1708 toselectively lock or allow actuation of the flexible extension tube ofthe proximal catheter in conjunction with the longitudinal depression ofthe knob 1702 by the user.

For the embodiments of FIGS. 16A-B and 17, a pump of the lever 1600 orthe knob 1702 or rotation of actuator knob 122 allows radial expansionof an associated implant by displacing the flexible extension tube 118distally or proximally as appropriate. During the deployment andextraction process the proximal and distal mounts 300 and 302 must movetoward each other to allow the implant to diametrally expand andsubsequently disengage from the implant 200. This is achieved by aplurality of means, both actively and passively. The rotation of knob122 allows precise control in both longitudinal directions.

Similarly, when the locking mechanism of the actuator 1706 and thelocking mechanism 1604 is released, the dual spring will contract anddisplace the flexible extension tube 118 of the proximal catheter 116 inthe proximal direction. An alternative method to the release mechanismis to utilize a detent that will establish a final click lock during theextension of the flexible extension tube 118, and such click with deployand fix into longitudinal place the flexible extension tube 118.Alternatively a passive mechanism is possible that the mounts aredisplaced past the point of full expansion and then drop away todisengage freely from the implant 200.

The embodiments discussed above have been discussed in detail inconnection with specific designs. It is to be understood, however, thatskilled artisans will be able to implement inventive features byemploying structures that may differ from the specific structuresdescribed above. Applicants in no way intend for the scope of theinventive features discussed herein to be limited to the specificstructure used in certain embodiments. For example, although in someillustrated embodiments only the distal-most mount has been activelymoved by the user, other embodiments may be made that employ inventiveaspects, but which instead actively move only the proximal-most mount,or which actively move both the proximal- and distal-most mountssimultaneously.

In the interest of clarity and consistency of discussion, theillustrated embodiments have been shown in the context of deploying animplant having a particular design. It is to be understood, however,that a variety of implant designs can be employed. For example, theillustrated implant included anchoring legs that would grasp tissue uponforeshortening during radial expansion. Other implant embodimentswithout anchoring legs can also be used with embodiments employingfeatures discussed herein. Additionally, the illustrated implant has aforeshortening portion and a non-foreshortening portion. It is to beunderstood that other stent designs having greater- or lesser-sizedforeshortening portions can be used, or even stents that have nonon-foreshortening portion. Additionally, stents having otherconfigurations of struts, cells and the like can be suitably employed.

In another embodiment, features discussed herein can be combined withother implant delivery apparatus and methods. For example, in oneembodiment, in addition to securing the implant under tension as inembodiments discussed above, the implant is also compacted and fitwithin a sheath, which helps to keep the implant in a small diametralconfiguration. In one embodiment, the sheath is located on the outersurface diameter of the implant and retains the implant in a diametrallyconstrained state. In such a configuration, the system holding theimplant under tension is a primary restraint system and the sheath ispart of a secondary restraint system.

In yet another embodiment, the delivery device may include a secondaryrestraint structure comprising a line or ribbon extending from a portionof the delivery device and circumferentially encircling the outside ofthe implant between proximal and distal ends of the implant. At leastone end of the line or ribbon can be tightened or let out by theoperator manipulating the controller. This secondary restraint works inconcert with the proximal and distal mounts to control radial expansionof the implant, and when the proximal and distal mounts are moved towardone another, the clinician can simultaneously let out the ribbon so asto allow the implant to expand. Once the implant is deployed, the ribboncan be retracted into the delivery device and removed from the patient.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In addition, while a number of variations of the invention havebeen shown and described in detail, other modifications, which arewithin the scope of this invention, will be readily apparent to those ofskill in the art based upon this disclosure, for example, the flexiblemembers 1200 can be used instead of sutures 312, 314. It is alsocontemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments may be made and stillfall within the scope of the invention. Accordingly, it should beunderstood that various features and aspects of the disclosedembodiments can be combined with or substituted for one another in orderto form varying modes of the disclosed invention. Thus, it is intendedthat the scope of the present invention herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims that follow.

What is claimed is:
 1. A method of delivering a self-expanding vascularimplant to a native valve, comprising: delivering a self-expandingvascular implant on a delivery system to the native valve, the deliverysystem retaining the vascular implant in a radially compactedconfiguration, wherein the delivery system comprises a ring mounted onan elongate support member, the ring comprising at least one slot, andwherein a suture received in the at least one slot extends from the ringand connects to the implant; allowing the self-expanding vascularimplant to expand, wherein tension on the suture controls expansion ofthe implant; and moving at least one of proximal and distal anchorsextending from the self-expanding vascular implant into engagement withan annulus of the native valve while the self-expanding vascular implantremains connected to the delivery system, wherein the self-expansion ofthe vascular implant causes the proximal and distal anchors to extendradially outwardly and to move closer to each other to grasp at leastone side of the annulus of the native valve between the distal anchorsand proximal anchors.
 2. The method of delivering a self-expandingvascular implant of claim 1, further comprising compacting theself-expanding vascular implant after allowing the self-expandingvascular implant to expand.
 3. The method of delivering a self-expandingvascular implant of claim 2, further comprising repositioning theimplant and allowing for re-expansion of the implant.
 4. The method ofdelivering a self-expanding vascular implant of claim 1, wherein thedelivery system retains the vascular implant in a radially compactedconfiguration by applying tension to the implant.
 5. The method ofdelivering a self-expanding vascular implant of claim 1, wherein thedelivery system retains the vascular implant in a radially compactedconfiguration by restraining the implant within a sheath.
 6. The methodof delivering a self-expanding vascular implant of claim 1, whereinallowing the self-expanding vascular implant to expand comprisesallowing the self-expanding vascular implant to partially expand.
 7. Themethod of delivering a self-expanding vascular implant of claim 6,further comprising allowing the self-expanding vascular implant tofurther expand after engaging the annulus of the native valve.
 8. Themethod of delivering a self-expanding vascular implant of claim 1,wherein a proximal end of the implant remains connected to the deliverysystem during expansion of the implant by engaging a portion of thedelivery system with a plurality of proximal interfaces on the implant.9. The method of delivering a self-expanding vascular implant of claim1, wherein the implant remains connected to the delivery system duringexpansion of the implant by engaging a portion of the delivery systemwith a distal end of the implant.
 10. A method of delivering aself-expanding vascular implant to a native valve, comprising:delivering a self-expanding vascular implant on a delivery system to thenative valve, the delivery system retaining the vascular implant in aradially compacted configuration, wherein the delivery system comprisesa first elongate member having a ring mounted thereon, the ringcomprising at least one slot, and a second elongate member extendingthrough the first elongate member having a nose cone at a distal endthereof, wherein a proximal portion of the implant is connected to theat least one slot in the ring and the implant is positioned at leastpartially between the ring and the nose cone; allowing theself-expanding vascular implant to expand; and moving at least one ofproximal and distal anchors extending from the self-expanding vascularimplant into engagement with an annulus of the native valve such thatthe proximal anchors are located on a first side of the native valveannulus and the distal anchors are located on a second side of thenative valve annulus opposite the first side.
 11. The method ofdelivering a self-expanding vascular implant of claim 10, wherein thering connected to the proximal portion of the implant during deliverycomprises a plurality of longitudinally-extending,circumferentially-spaced slots.
 12. The method of delivering aself-expanding vascular implant of claim 10, wherein the delivery systemcomprises a gap proximal to the plurality of longitudinally-extending,circumferentially-spaced slots.
 13. The method of delivering aself-expanding vascular implant of claim 10, wherein the proximalportion of the implant that connects to the at least one slot in thering during delivery comprises a plurality of spaced apart interfaces.14. The method of delivering a self-expanding vascular implant of claim13, wherein the plurality of spaced apart interfaces have a geometryselected from the group consisting of an eyelet, a hook, a radiused orsharp angled triangle element, a block, a sphere and a t-shaped leg. 15.The method of delivering a self-expanding vascular implant of claim 13,wherein the plurality of spaced apart interfaces that connect to the atleast one slot in the ring during delivery are provided at a proximalend of the implant.
 16. The method of delivering a self-expandingvascular implant of claim 13, wherein the plurality of spaced apartinterfaces that connect to the at least one slot in the ring duringdelivery are provided at an intermediate location on the implant. 17.The method of delivering a self-expanding vascular implant of claim 10,wherein during delivery, the proximal portion of the implant isconnected to the at least one slot in the ring with a suture.
 18. Themethod of delivering a self-expanding vascular implant of claim 10,wherein the delivery system further comprises a sheath provided over theimplant to radially compact the implant, and wherein allowing theself-expanding vascular implant to expand comprises at least partiallyremoving the sheath from the implant.
 19. The method of delivering aself-expanding vascular implant of claim 10, wherein during delivery,the delivery system is connected to a distal portion of the implant. 20.The method of delivering a self-expanding vascular implant of claim 19,wherein during delivery, the delivery system comprises a distal ringcomprising a plurality of slots connected to the distal portion of theimplant.